Dental instrument.



e. H. BRETSCH. DENTAL INSTRUMENT.

APPLIQATION FILED DEC- 13. I913.

1,152,21, Patented Aug. 31, 1915.

GARFIELD H. BRETSCH. OF SAN DIEGO, CALIFORNIA.

DENTAL INSTRUMENT.

Specification of Letters Patent.

Patented Aug. 31, 1915..

Application filed December 13, 1913. Serial No. 806,530.

To all whom it may concern:

Be it knownthat I, GARFIELD H. BRn'rsoH, a citizen of the United States, residing at San Diego, in the county'of San Diego and State of California, have invented certain new and useful Improvements in Dental Instruments; and I do hereby declare the following to be'a full, clear, and exact de scription of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to new and useful improvements in dental instruments, more particularly to an instrument for sharpening the exposed ends of pins earned by a porcelain facing or tooth used in dentistry in the manufacture of crown and bridge work.

An important object of my invention 1s to provide a tool such as above described that is adapted to be rotatably connected with a dental engine or like machine and is particularly designed for sharpening the ends of pins carried by porcelain 'facings or teeth that are adapted to be backed .with platinum or gold plates.

Heretofore in dentistry it has been the custom to punch holes with a plate punch through a backing plate of gold or platinum for a porcelain facing or tooth in the construction of crowns or bridge work for teeth and to insert the facing pins through-the openings in the backing plate.

My invention aims to provide a simple and reliable tool whereby the pins carried by the porcelain facings or teeth may be readily and evenly sharpened whereby they may be inserted through the usual gold or platinum backing plates and provide a tight connection where inserted through the backing plates as heretofore in havingholes punched through the backing plates and the pins in serted therethrough, a tight connection was not provided.

A still further object of my invention is to provide a device such as above described which is simple as to construction and arrangement of parts may be cheaply manufactured and is capable of being readily attached to dental engines or like machines.

The above and additional objects are accomplished by such means as are illustrated in the accompanying drawings, described in the following specification and then more particularly pointed out in the claims which are appended hereto and form a part of this application.

Withreference to the drawings, wherein I have illustrated the preferred embodiment of my invention as it is reduced to practice, throughout the several views of which, similar reference numerals designate correspond ing parts: Figure 1 is atop plan view of my device as it would appear in assembled position, Fig. 2 is a longitudinal sectional view taken on line 22 of Fig. 1 illustrating the relative positions of the several parts of my device when in assembled position, Fig. 3 is a cross sectional view taken on line 33 of Fig. 2, and Fig. 4 is a cross sectional View taken 011 line H of Fig. 2.

Referring now more particularly to the drawings forming a part of this specification and in which like numerals are employed to designate corresponding parts, the numeral 1 designates as an entirety a shank of a cylindrical form that is adapted for operative connection with a chuck not shown of the usual dental machine or lathe. This shank 1 is provided with an enlarged cylindrical body portion 2 at one terminal that is provided adjacent with screw threads 3 for a purpose which will be later more fully disclosed.

Formed within the enlarged portion 2 of the shank 1 is a longitudinally extending groove or slot 4- that terminates adjacent the outer terminal of the portion 2 in a restricted annular opening 5 that is adapted to have the pins carried by the porcelain facings or teeth inserted therein to be sharpened after a manner which will be later more fully described. The free end of the enlarged portion 2 is reduced as at 6 to facilitate the positioning of the tool for sharpening the pins as hereinbefore described when the pins are arranged in close relation to each other.

Mounted within the groove 4 is a sharpening member 7 that is approximately rectangular in shape and constructed of some suitable hardened material. This sharpening member 7 is reduced at its forward ter minal upon one side thereof as at 8 and pro vided upon the opposite side adjacent the forward end thereof with an inclined face and cutting edge 9 extending angularly with relation to the opening 5 in the end of the Mounted upon the enlarged portion-2 is a cylindrical sleeve or collar 10 provided at one terminal with internal screw threads adapted to engage the screw threads. 3 on the enlarged portion 2 Wherebythe sleeve is held in engagement with the sharpening member 7 serves to hold it in placewithin the grooveor' recesslfas will'beclearly seen with i'eference to 2 in the drawings a p The sleeve 10 is provided adj acentits internallyjscrew threaded terminal with a pair of annular spaced gripping ribs 11 that may be. knurled to provide for a better gripping engagement, of; "a suitable tool or fingers when it is desired todisassemble or assemble the. tool;

cylindrical sleeve 10 is, when secured uponthe enlarged .portion 2. after the manner. hereinbefore. described, spaced at 7 its outer end with relation to the-outer reduced portion-6 of the enlarged portion 2. for a purgosewhich-will be latermore fully decri d-.. y

Formed integral with the sharpening member 7g'adjacent the outer longitudinal edge thereof and .at a point near the reduced portion 8 thereof is. an upstanding lug 12.

I This lug 12L-is adapted for engagement with the. adji' Centedge of: thecylindrical sleeve 10 .anldise'rves to hold the, sharpening IHQIYL'. her 7 in thendesired position. within the recessfor, groove 4 ofthe enlarged portion 2 of the shank 1.

Having fully described thestructural de tails] ofmy invention it now remains to take up the description of theoperation which. may be briefly outlined. as follows; The shank .1' is operatively connected with a suitable dental lathe or like machine such as commonly employed by dentists for operating their various tools and provision for the rotation of the tool is had. To sharpen the pins carried by the facings of porcelain. or teeth carrying'pins the reduced portion 6 of the enlarged portion 2 of the shank lis placed .so that one of the pins is disposed Within the opening 5 and in a position for engagement with theinclined face and cuttingedge 9 of the sharpening member. 7. Uponthe rotation of the enlarged portion 2 it willbe. readily seen, that the ends of the, pins after being inserted within the opening 5 and disposed in engagement with the cutting edge 9 of the member 7 are readily sharpened. I The points produced on the ends of'the pins by the tool ashereinbefore described isa smooth conical one that -12 constant use of the device would result inthe-shaking loose of the cuttingelement 7 since it, engages at two points the holder therefor. By tightening or turning the sleeve 10 it will be seen that the cutting element 7 will be securely clamped in the holder since the lug 12 engages said sleeve.

It is apparent, withreference to the foregoing description and accompanying drawings that. there has been provided a dental instrument which will permit the sharpening of pins carriedupon porcelain facings or teeth in a reliableandexpeditious manner and-while the tool is designed particularly foruse in connection with the purpose above mentioned it may be used .to sharpen thepointsof various instrumentsemployed by. dentists. as wel-Las-for the primary purpose intended.

In; reduction, to practice, I have found that the form of.- my invention, illustrated in the drawings and referred to in the above description,- as the. preferred embodiment, isthe mosteflicient. andipractical; yet realizing thattheconditions concurrent with theadoptionpfmy device will necessarily vary, ,I, desire to-emplmasize. the fact that various minor changes-in details of construction, proportion. and arrangement of parts may be resorted to, when required, without. sacrificing; any of theradvantages of my invention; as? defined inthe appended claims.

. lVhatisrclaimed is l. Adental instrumentcomprising ancylindrical bodyportion. having-a longitudinal groove in one side thereof and an opening in its-outer end communicating with said groove, a sharpening member mounted within, said groove and engaging; the ends thereof atits ends, said sharpening member being spaced iits entire length from one side ofthe groove and havingan inclined face 7 opposite to said opening, an outstanding cylindrical internally screw threaded sleeve her and engaging the outer end of said 10 mounted upon the body portion and receiv-. sleeve. 4

ing the greater part of said sharpening In testimony whereof I afiix my signature 7 member, said sharpening member engaging in presence of two Witnesses.

at its ends the ends of said groove and having the face thereof which is opposite to said GARFIELD BRETSOH' opening inclined and arranged for engage- Witnesses:

ment With objects inserted in said opening W. A. BOLTON,

and a lug carried by said sharpening mem- O. A. BUGKLAND.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0; 

